Display device

ABSTRACT

Disclosed is a display device capable of reducing the thickness and the weigh thereof. A display device having a touch sensor realizes electrical connection of a routing line and a touch pad via an auxiliary conductive layer, which is connected to the routing line under an encapsulation unit, even if a disconnection fault occurs in the routing line, thereby achieving increased yield and reliability. In addition, through the provision of a touch sensor disposed above the encapsulation unit, a separate attachment process is unnecessary, which results in a simplified manufacturing process and reduced costs.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.17/113,982, filed Dec. 7, 2020, which is a continuation of U.S. patentapplication Ser. No. 16/834,218, filed Mar. 30, 2020, which is acontinuation of U.S. patent application Ser. No. 15/976,761, filed May10, 2018, which claims the benefit of Korean Patent Application No.10-2017-0058637, filed May 11, 2017, which applications are herebyincorporated by reference as if fully set forth herein.

BACKGROUND Technical Field

The present disclosure relates to a display device, and moreparticularly, to a display device capable of achieving a simplifiedmanufacturing process and reduced costs.

Description of the Related Art

A touchscreen is an input device that allows a user to input a commandby selecting a content appearing on a screen of a display device or thelike with the human hand or an object. That is, the touchscreen convertsa contact position that the human hand or the object directly touchesinto an electrical signal, and receives the content selected at thecontact position as an input signal. The touchscreen may substitute fora separate input device, which is connected to the display device andoperates, such as a keyboard or a mouse, and thus the use range thereofis gradually expanding.

Such a touchscreen is generally attached to the front surface of adisplay panel, such as a liquid crystal display panel or an organiclight-emitting diode display panel, via an adhesive in many cases. Inthis case, since the touchscreen is separately manufactured and attachedto the front surface of the display panel, the manufacturing process iscomplicated and the costs are increased due to addition of such anattachment process.

BRIEF SUMMARY

Accordingly, the present disclosure is directed to a display device thatsubstantially obviates one or more problems due to limitations anddisadvantages of the related art.

The present disclosure has been provided to solve the problems describedabove, and in various embodiments, the present disclosure provides adisplay device capable of achieving a simplified manufacturing processand reduced costs.

Additional advantages, objects, and features of the disclosure will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of thedisclosure. The objectives and other advantages of the disclosure may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the disclosure, as embodied and broadly described herein, adisplay device having a touch sensor realizes electrical connection of arouting line and a touch pad via an auxiliary conductive layer, which isconnected to the routing line under an encapsulation unit, even if adisconnection fault occurs in the routing line, thereby achievingincreased yield and reliability. In addition, through the provision of atouch sensor disposed above the encapsulation unit, a separateattachment process is unnecessary, which results in a simplifiedmanufacturing process and reduced costs.

It is to be understood that both the foregoing general description andthe following detailed description of the present disclosure areexemplary and explanatory and are intended to provide furtherexplanation of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the disclosure andtogether with the description serve to explain the principle of thedisclosure. In the drawings:

FIG. 1 is a perspective view illustrating an organic light-emittingdiode display device having a touch sensor according to a firstembodiment of the present disclosure;

FIG. 2 is a plan view illustrating the organic light-emitting diodedisplay device having the touch sensor illustrated in FIG. 1 ;

FIG. 3 is a cross-sectional view illustrating the organic light-emittingdiode display device having the touch sensor taken along line I-I′ ofFIG. 2 ;

FIG. 4 is a cross-sectional view illustrating another embodiment of anauxiliary conductive layer illustrated in FIG. 3 ;

FIG. 5 is a cross-sectional view illustrating another embodiment of anauxiliary contact hole illustrated in FIG. 3 ;

FIG. 6 is a perspective view for explaining a connection relationshipbetween a routing line and a touch pad via the auxiliary conductivelayer illustrated in FIG. 3 ;

FIG. 7 is a cross-sectional view illustrating a touch driving integratedcircuit connected to the touch pad illustrated in FIG. 3 ;

FIG. 8 is a cross-sectional view illustrating an organic light-emittingdiode display device having a touch sensor according to a secondembodiment of the present disclosure; and

FIGS. 9A and 9B are a plan view and a cross-sectional view,respectively, illustrating another embodiment of first and second touchelectrodes and bridges illustrated in FIGS. 2 and 3 .

DETAILED DESCRIPTION

Hereinafter, embodiments according to the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view illustrating an organic light-emittingdiode display device having a touch sensor according to the presentdisclosure.

The organic light-emitting diode display device having a touch sensorillustrated in FIG. 1 senses the presence or absence of a touch and atouch position by sensing a variation in mutual capacitance Cm (touchsensor) in response to a user touch via touch electrodes 152 e and 154 eillustrated in FIG. 2 for a touch period. Then, the organiclight-emitting diode display device having a touch sensor illustrated inFIG. 1 displays an image via unit pixels each including a light-emittingelement 120. Each unit pixel may include red (R), green (G), and blue(B) subpixels PXL, or may include red (R), green (G), blue (B), andwhite (W) subpixels PXL.

To this end, the organic light-emitting diode display device illustratedin FIG. 1 includes a plurality of subpixels PXL arranged in a matrixform on a substrate 111 formed of a flexible material or a glassmaterial, an encapsulation unit 140 disposed on the subpixels PXL, and amutual capacitance array Cm disposed on the encapsulation unit 140.

Each of the subpixels PXL includes a pixel drive circuit and thelight-emitting element 120 connected to the pixel drive circuit.

The pixel drive circuit includes a switching transistor T1, a drivingtransistor T2, and a storage capacitor Cst. Meanwhile, in the presentdisclosure, a structure in which the pixel drive circuit includes twotransistors T and one capacitor C has been described by way of example,but the present disclosure is not limited thereto. That is, a pixeldrive circuit having a 3T1C structure or 3T2C structure in which threeor more transistors T and one or more capacitors C are provided may beused.

The switching transistor T1 is turned on when a scan pulse is suppliedto a scan line SL, and supplies a data signal supplied to a data line DLto the storage capacitor Cst and a gate electrode of the drivingtransistor T2.

The driving transistor T2 controls current to be supplied from ahigh-voltage (VDD) supply line to the light-emitting element 120 inresponse to the data signal supplied to the gate electrode of thedriving transistor T2, thereby adjusting the amount of emission of lightfrom the light-emitting element 120. Then, even if the switchingtransistor T1 is turned off, the driving transistor T2 maintains theemission of light of the light-emitting element 120 by supplying aconstant amount of current thereto by a voltage charged in the storagecapacitor Cst until a data signal of a next frame is supplied.

The driving transistor T2 or 130, as illustrated in FIG. 3 , includes asemiconductor layer 134 disposed on a buffer layer 112, a gate electrode132 overlapping the semiconductor layer 134 with a gate insulation layer102 therebetween, and source and drain electrodes 136 and 138 formed onan interlayer insulation layer 114 to come into contact with thesemiconductor layer 134. Here, the semiconductor layer 134 is formed ofat least one of an amorphous semiconductor material, a polycrystallinesemiconductor material, and an oxide semiconductor material.

The light-emitting element 120 includes an anode electrode 122, at leastone light-emitting stack 124 formed on the anode electrode 122, and acathode electrode 126 formed on the light-emitting stack 124.

The anode electrode 122 is electrically connected to the drain electrode138 of the driving transistor T2 or 130, which is exposed through apixel contact hole penetrated through a protective layer 116 and a pixelplanarization layer 118.

The light-emitting stack 124 is formed on the anode electrode 122 in alight-emitting area that is defined by a bank 128. The light-emittingstack 124 is formed by stacking a hole-related layer, an organicemission layer, and an electron-related layer on the anode electrode 122in this order or in the reverse order. In addition, the at least onelight-emitting stack 124 may include first and second light-emittingstacks, which face each other with a charge generation layertherebetween. In this case, the organic emission layer of any one of thefirst and second light-emitting stacks generates blue light, and theorganic emission layer of the other one of the first and secondlight-emitting stacks generates yellow-green light, whereby white lightis generated via the first and second light-emitting stacks. Since thewhite light generated in the light-emitting stack 124 is incident on acolor filter located above or under the light-emitting stack 124, acolor image may be realized. In addition, colored light corresponding toeach subpixel may be generated in each light-emitting stack 124 torealize a color image, without a separate color filter. That is, thelight-emitting stack 124 of the red (R) subpixel may generate red light,the light-emitting stack 124 of the green (G) subpixel may generategreen light, and the light-emitting stack 124 of the blue (B) subpixelmay generate blue light.

The cathode electrode 126 may be formed so as to face the anodeelectrode 122 with the light-emitting stack 124 therebetween, and isconnected to a low-voltage (VSS) supply line.

The encapsulation unit 140 prevents external moisture or oxygen fromentering the light-emitting element 120, which is vulnerable to theexternal moisture or oxygen. To this end, the encapsulation unit 140includes a plurality of inorganic encapsulation layers 142 and 146 andan organic encapsulation layer 144 disposed between the inorganicencapsulation layers 142 and 146. The inorganic encapsulation layer 146is the uppermost layer. Here, the encapsulation unit 140 includes atleast two inorganic encapsulation layers 142 and 146 and at least oneorganic encapsulation layer 144. In the present disclosure, thestructure of the encapsulation unit 140 in which the organicencapsulation layer 144 is disposed between the first and secondinorganic encapsulation layers 142 and 146 will be described by way ofexample.

The first inorganic encapsulation layer 142 is formed on the substrate111, on which the cathode electrode 126 has been formed, so as to beclosest to the light-emitting element 120. The first inorganicencapsulation layer 142 is formed of an inorganic insulation materialthat is capable of being deposited at a low temperature, such as siliconnitride (SiN_(x)), silicon oxide (SiO_(x)), silicon oxide nitride(SiON), or aluminum oxide (Al₂O₃). Thus, since the first inorganicencapsulation layer 142 is deposited under a low-temperature atmosphere,it is possible to prevent damage to the light-emitting stack 124, whichis vulnerable to a high-temperature atmosphere, during the depositionprocess of the first inorganic encapsulation layer 142.

The organic encapsulation layer 144 serves to dampen stress between therespective layers due to bending of the organic light-emitting diodedisplay device and to increase planarization performance. The organicencapsulation layer 144 is formed on the substrate 111, on which thefirst inorganic encapsulation layer 142 has been formed, using anorganic insulation material, such as an acryl resin, epoxy resin,polyimide, polyethylene, or silicon oxycarbide (SiOC).

The second inorganic encapsulation layer 146 is formed on the substrate111, on which the organic encapsulation layer 144 has been formed, so asto cover the upper surface and the side surface of each of the organicencapsulation layer 144 and the first inorganic encapsulation layer 142.Thus, the second inorganic encapsulation layer 146 minimizes or preventsexternal moisture or oxygen from entering the first inorganicencapsulation layer 142 and the organic encapsulation layer 144. Thesecond inorganic encapsulation layer 146 is formed of an inorganicinsulation material, such as silicon nitride (SiN_(x)), silicon oxide(SiO_(x)), silicon oxide nitride (SiON), or aluminum oxide (Al₂O₃).

On the encapsulation unit 140, a touch buffer layer 148 is disposed. Thetouch buffer layer 148 is formed between each of a touch sensing line154 and a touch driving line 152 and the light-emitting element 120 sothat the distance between each of a touch sensing line 154 and a touchdriving line 152 and the cathode electrode 126 is maintained at theminimum 5 μm. Thereby, the capacitance of a parasitic capacitor formedbetween each of the touch sensing line 154 and the touch driving line152 and the cathode electrode 126 may be minimized, and mutualinteraction due to coupling between each of the touch sensing line 154and the touch driving line 152 and the cathode electrode 126 may beprevented. Meanwhile, when the distance between each of a touch sensingline 154 and a touch driving line 152 and the cathode electrode 126 isbelow 5 μm, touch performance deteriorates due to the mutual interactiondue to coupling between each of the touch sensing line 154 and the touchdriving line 152 and the cathode electrode 126.

In addition, the touch buffer layer 148 may prevent a chemical solution(e.g., developing solution or etching solution) used in the process ofmanufacturing the touch sensing line 154 and the touch driving line 152,external moisture, and the like from entering the light-emitting stack124. Thereby, the touch buffer layer 148 may prevent damage to thelight-emitting stack 124, which is vulnerable to the chemical solutionor moisture.

The touch buffer layer 148 may be formed at a low temperature that isequal to or less than 100° C., and may be formed of an organic orinorganic insulation material having a low dielectric constant rangingfrom 1 to 3, in order to prevent damage to the light-emitting stack 124,which is vulnerable to high temperatures. For example, the touch bufferlayer 148 is formed of an acryl-based, epoxy-based, or siloxane-basedmaterial. The touch buffer layer 148 formed of an organic insulationmaterial serves to damage to the respective encapsulation layers 142,144 and 146 of the encapsulation unit 140 and the breakage of the touchsensing line 154 and the touch driving line 152 formed on the touchbuffer layer 148 due to bending of the organic light-emitting diodedisplay device.

On the touch buffer layer 148, the touch sensing line 154 and the touchdriving line 152 are disposed so as to intersect each other with a touchinsulation layer 168 between these 154 and 152 and the touch bufferlayer 148. The term “intersect” is used herein to mean that one elementcrosses over or overlaps another element, and does not necessarily meanthat the two elements contact each other. The mutual capacitance arrayCm is formed at the intersection of the touch sensing line 154 and thetouch driving line 152. Thus, the mutual capacitance array Cm serves asa touch sensor by storing charges in response to a touch driving pulsesupplied to the touch driving line 152 and discharging the stored chargeto the touch sensing line 154.

The touch driving line 152 includes a plurality of first touchelectrodes 152 e, and first bridges 152 b, which electricallyinterconnect the first touch electrodes 152 e.

The first touch electrodes 152 e are equidistantly spaced apart fromeach other in the Y-direction, which is a first direction, on the touchinsulation layer 168. Each of the first touch electrodes 152 e iselectrically connected to an adjacent first touch electrode 152 e viathe first bridge 152 b.

The first bridge 152 b is disposed on the touch insulation layer 168 inthe same plane as the first touch electrode 152 e, and is electricallyconnected to the first touch electrode 152 e without a separate contacthole. Since the first bridge 152 b is disposed so as to overlap the bank128, it is possible to prevent deterioration in the aperture ratio dueto the first bridge 152 b.

The touch sensing line 154 includes a plurality of second touchelectrodes 154 e, and second bridges 154 b, which electricallyinterconnect the second touch electrodes 154 e.

The second touch electrodes 154 e are equidistantly spaced apart fromeach other in the X-direction, which is a second direction, on the touchinsulation layer 168. Each of the second touch electrodes 154 e iselectrically connected to an adjacent second touch electrode 154 e viathe second bridge 154 b.

The second bridge 154 b is formed on the touch buffer layer 148, and isexposed through a touch contact hole 150, which is penetrated throughthe touch insulation layer 168, so as to be electrically connected tothe second touch electrode 154 e. The second bridge 154 b is disposed soas to overlap the bank 128, in the same manner as the first bridge 152b, which may prevent damage to the aperture ratio due to the secondbridge 154 b.

In this way, the touch driving line 152 and the touch sensing line 154of the present disclosure are connected respectively to a touch pad 170via a routing line 156.

The routing line 156 extends from the first touch electrode 152 e to atleast one of the upper side and the lower side of an active area AA soas to be connected to the touch pad 170. The routing line 156 alsoextends from the second touch electrode 154 e to at least one of theright side and the left side of the active area so as to be connected tothe touch pad 170. The arrangement of the routing line 156 may bechanged in various ways according to design requirements of the displaydevice.

The routing line 156 is formed between each of the first and secondtouch electrodes 152 e and 154 e and the touch pad 170, and electricallyinterconnects each of the first and second touch electrodes 152 e and154 e and the touch pad 170. The upper portion of the routing line 156is exposed through a routing contact hole 158, which is penetratedthrough the touch insulation layer 168, and is electrically connected toeach of the first and second touch electrodes 152 e and 154 e above theencapsulation unit 140. The side portion of the routing line 156, asillustrated in FIG. 3 , may be disposed so as to cover the side surfaceof the touch buffer layer 148 in the display device having the touchbuffer layer 148, or may be disposed so as to cover the side surface ofthe second inorganic encapsulation layer 146 in the display devicehaving no touch buffer layer 148. In addition, the lower portion of therouting line 156 is disposed on one of the touch buffer layer 148, theplanarization layer 118, the protective layer 116, the interlayerinsulation layer 114, the gate insulation layer 102, and the bufferlayer 112, which are insulation layers disposed under the first andsecond touch electrodes 152 e and 154 e.

In addition, the routing line 156, as illustrated in FIG. 3 or 4 , isconnected to an auxiliary conductive layer 172 through an auxiliarycontact hole 176 under the encapsulation unit 140, and the auxiliaryconductive layer 172 is connected to the touch pad 170 through a padcontact hole 174. To this end, the auxiliary conductive layer 172, asillustrated in FIGS. 2 to 4 , is formed under the routing line 156 andthe touch pad 170 so as to extend along the routing line 156 and thetouch pad 170.

Specifically, the auxiliary conductive layer 172 illustrated in FIG. 3is formed using the same material as the source and drain electrodes 136and 138, and is disposed on the interlayer insulation layer 114 in thesame plane as the electrodes 136 and 138. The auxiliary conductive layer172 is exposed through the auxiliary contact hole 176, which ispenetrated through the touch buffer layer 148, the encapsulation unit140, and the protective layer 116, and is connected to the routing line156. The auxiliary conductive layer 172 is also exposed through the padcontact hole 174, which is penetrated through the touch buffer layer 148and the protective layer 116, and is connected to the touch pad 170.

The auxiliary conductive layer 172 illustrated in FIG. 4 is formed usingthe same material as one of the anode electrode 122 and the cathodeelectrode 126, and is disposed on the protective layer 116. Theauxiliary conductive layer 172 is exposed through the auxiliary contacthole 176, which is penetrated through the touch buffer layer 148 and theencapsulation unit 140, and is connected to the routing line 156. Theauxiliary conductive layer 172 is also exposed through the pad contacthole 174, which is penetrated through the touch buffer layer 148, and isconnected to the touch pad 170. Here, each of the auxiliary contact hole176 and the pad contact hole 174 illustrated in FIG. 4 has a depthsmaller than that of each of the auxiliary contact hole 176 and the padcontact hole 174 illustrated in FIG. 3 . Thus, each of the auxiliarycontact hole 176 and the pad contact hole 174 illustrated in FIG. 4enables reduction in the number of processes and the processing time,thus resulting in an increased process margin, compared to each of theauxiliary contact hole 176 and the pad contact hole 174 illustrated inFIG. 3 .

Meanwhile, the structure in which the side surface of the organicencapsulation layer 144 illustrated in FIGS. 3 and 4 is exposed throughthe auxiliary contact hole 176, which is penetrated through theplurality of inorganic encapsulation layers 142 and 146 and the at leastone organic encapsulation layer 144 has been described by way ofexample, alternatively, as illustrated in FIG. 5 , the side surface ofthe organic encapsulation layer 144 in the area corresponding to theauxiliary contact hole 176 may be covered with the second inorganicencapsulation layer 146, which is the uppermost layer among theplurality of inorganic encapsulation layers. In this way, the secondinorganic encapsulation layer 146 may minimize or prevent externalmoisture or oxygen from entering the side surface of the organicencapsulation layer 144 in the area corresponding to the auxiliarycontact hole 176.

In this way, the auxiliary conductive layer 172 illustrated in FIGS. 3to 5 is connected to the routing line 156 as well as the touch pad 170.Thus, due to the stepped and tapered shape of the organic encapsulationlayer 144, as illustrated in FIG. 6 , the routing line 156 is connectedto the touch pad 170 via the auxiliary conductive layer 172 even if therouting line 156 is disconnected at the boundary of the organicencapsulation layer 144. In particular, in the case where the displaydevice of the present disclosure is applied to a flexible display, suchas a rollable, bendable, foldable, or stretchable display, the auxiliaryconductive layer 172 receives lower bending stress than the routing line156. That is, since at least one of the protective layer and theencapsulation unit is disposed so as to cover the auxiliary conductivelayer 172, the auxiliary conductive layer 172 disposed under the routingline 156 is not damaged by the stress due to the bending of a pad area.Thereby, even if the routing line 156, on which bending stress isconcentrated, is disconnected, the routing line 156 may be connected tothe touch pad 170 via the auxiliary conductive layer 172, and therefore,the present disclosure may prevent poor reliability caused in the caseof a flexible display.

In addition, through the stepped and tapered shape of the organicencapsulation layer 144, a photoresist pattern (not illustrated) forpatterning the routing line 156 disposed on the encapsulation unit 140may be partially removed, or may excessively remain. When the routingline 156 is patterned using the partially removed photoresist pattern, adisconnection fault of the routing line 156 occurs at the boundary ofthe organic encapsulation layer 144. However, in the present disclosure,as illustrated in FIG. 6 , even if the routing line 156 is disconnectedat the boundary of the organic encapsulation layer 144, the routing line156 is connected to the touch pad 170 via the auxiliary conductive layer172, which may result in increased yield and reliability. In addition,when the routing line 156 is patterned using the excessively remainingphotoresist pattern, short-circuit of adjacent routing lines may occurat the boundary of the organic encapsulation layer 144. However, in thepresent disclosure, the routing lines 156, which have undergoneshort-circuit, may be separated through a repair process using a laseror the like, which results in increased yield. In addition, even if therouting line 156 is disconnected due to a process fault during therepair process, as illustrated in FIG. 6 , the routing line 156 may beconnected to the touch pad 170 via the auxiliary conductive layer 172.

The touch pad 170 is disposed on either side of the area in which adisplay pad is disposed so as to be connected to at least one of thescan line SL and the data line DL disposed in the active area. The touchpad 170 may be disposed on one side of the display panel, and thedisplay pad may be disposed on the other side of the display panel.

The touch pad 170 extends from the routing line 156 and is connected tothe routing line 156. To this end, the touch pad 170 is formed throughthe same mask process using the same material as the routing line 156.

The touch pad 170 may be formed through the same mask process as atleast one of the first touch electrode 152 e and the second touchelectrode 154 e using the same material as at least one of the firsttouch electrode 152 e and the second touch electrode 154 e.

The touch pad 170, as illustrated in FIG. 7 , is connected to a touchdriving integrated circuit 104 via a signal transmission film 106including conductive particles 108. Thus, a touch driving pulsegenerated in the touch driving integrated circuit 104 is transmitted tothe touch driving line 152 via the touch pad 170 and the routing line156, and a touch signal from the touch sensing line 154 is transmittedto the touch driving integrated circuit 104 via the routing line 156 andthe touch pad 170.

In this way, in the present disclosure, the auxiliary conductive layer172 is connected to the routing line 156 as well as the touch pad 170.Thereby, even if a disconnection fault occurs in the routing line 156,the routing line 156 and the touch pad 170 are electrically connected toeach other via the auxiliary conductive layer 172, which may result inincreased yield and reliability. In addition, a conventional organiclight-emitting diode display device includes a touchscreen attachedthereto using an adhesive, whereas an organic light-emitting diodedisplay device of the present disclosure includes the touch electrodes152 e and 154 e disposed on the encapsulation unit 140, which may make aseparate attachment process be unnecessary, resulting in a simplifiedmanufacturing process and reduced costs.

FIG. 8 is a cross-sectional view illustrating an organic light-emittingdiode display device according to a second embodiment of the presentdisclosure.

The organic light-emitting diode display device illustrated in FIG. 8includes the same constituent elements as those of the organiclight-emitting diode display device illustrated in FIG. 3 , except thatit further includes color filters 192 disposed between the encapsulationunit 140 and the touch electrodes 152 e and 154 e. Thus, a detaileddescription related to the same constituent elements will be omittedbelow.

The color filters 192 are formed between each of the touch sensing line154 and the touch driving line 152 and the light-emitting element 120.The distance between each of the touch sensing line 154 and the touchdriving line 152 and the light-emitting element 120 is increased by thecolor filters 192. Thereby, the capacitance of a parasitic capacitorformed between each of the touch sensing line 154 and the touch drivingline 152 and the light-emitting element 120 may be minimized, and mutualinteraction due to coupling between each of the touch sensing line 154and the touch driving line 152 and the light-emitting element 120 may beprevented. In addition, the color filters 192 may prevent a chemicalsolution (e.g., developing solution or etching solution) used in theprocess of manufacturing the touch sensing line 154 and the touchdriving line 152, external moisture, and the like from entering thelight-emitting stack 124. Thereby, the color filters 192 may preventdamage to the light-emitting stack 124, which is vulnerable to thechemical solution or moisture. Meanwhile, as illustrated in FIG. 8 , theconfiguration in which the touch electrodes 152 e and 154 e are disposedover the color filters 192 has been described by way of example, but thecolor filters 192 may be disposed over the touch electrodes 152 e and154 e. In this case, the touch electrodes 152 e and 154 e are disposedbetween the color filters 192 and the encapsulation unit 140.

A black matrix 194 is disposed between the color filters 192. The blackmatrix 194 serves to separate the respective subpixel areas from eachother and to prevent optical interference and light leakage betweenadjacent subpixel areas. The black matrix 194 may be formed of ahigh-resistance black insulation material, or may be formed by stackingat least two colors of color filters among red (R), green (G), and blue(B) color filters 192. In addition, a touch planarization layer 196 isformed on the substrate 111 having the color filters 192 and the blackmatrix 194 formed thereon. The substrate 111 having the color filters192 and the black matrix 194 formed thereon is flattened by the touchplanarization layer 196.

In this way, in the present disclosure, the auxiliary conductive layer172 is connected to the routing line 156 as well as the touch pad 170.Thereby, even if short-circuit occurs in the routing line 156, therouting line 156 and the touch pad 170 are electrically connected toeach other via the auxiliary conductive layer 172, which may result inincreased yield and reliability. In addition, a conventional organiclight-emitting diode display device includes a touchscreen attachedthereto using an adhesive, whereas an organic light-emitting diodedisplay device of the present disclosure includes the touch electrodes152 e and 154 e disposed on the encapsulation unit 140, which may make aseparate attachment process be unnecessary, resulting in a simplifiedmanufacturing process and reduced costs.

Meanwhile, in the present disclosure, the configuration in which thefirst and second touch electrodes 152 e and 154 e and the first andsecond bridges 152 b and 154 b are formed to have a plate shape, asillustrated in FIG. 2 , has been described by way of example, the firstand second touch electrodes 152 e and 154 e and the first and secondbridges 152 b and 154 b may be formed to have a mesh shape, asillustrated in FIGS. 9A and 9B. That is, the first and second touchelectrodes 152 e and 154 e and the first bridge 152 b may be formed of atransparent conductive layer 1541, such as ITO or IZO, and a mesh metallayer 1542 disposed above or under the transparent conductive layer 1541and having a mesh shape. Alternatively, the touch electrodes 152 e and154 e and the first bridge 152 b may be formed of only the mesh metallayer 1542 without the transparent conductive layer 1541, or may beformed of the transparent conductive layer 1541 having a mesh shapewithout the mesh metal layer 1542. Here, the mesh metal layer 1542 isformed to have a mesh shape using a conductive layer of at least one ofTi, Al, Mo, MoTi, Cu, Ta, and ITO, so as to have higher conductivitythan the transparent conductive layer 1541. For example, the mesh metallayer 1542 is formed in a triple-layered structure as a stack ofTi/Al/Ti, MoTi/Cu/MoTi, or Ti/Al/Mo. Thereby, the resistance and thecapacitance of the first and second touch electrodes 152 e and 154 e andthe first bridge 152 b may be reduced, and the RC time constant may bereduced, which may result in increased touch sensitivity. In addition,since the mesh metal layer 1542 of each of the first and second touchelectrodes 152 e and 154 e and the first bridge 152 b has a very smallline width, it is possible to prevent deterioration in the apertureratio and transmissivity due to the mesh metal layer 1542.

In addition, the second bridge 154 b, which is disposed in a planedifferent from the touch electrodes 152 e and 154 e, includes aplurality of slits 153, as illustrated in FIGS. 9A and 9B. The secondbridge 154 b having the slits 153 may have a reduced surface area,compared to the first bridge 152 b having no slit 153. Thereby, thereflection of external light by the second bridge 154 b may be reduced,which may prevent deterioration in visibility. Since the second bridge154 b having the slits 153 overlaps the bank 128, it is possible toprevent deterioration in the aperture ratio by the second bridge 154 bformed of an opaque conductive layer.

Moreover, in the present disclosure, the mutual-capacitance-type touchsensor, which includes the touch sensing line 154 and the touch drivingline 152 intersecting each other with the touch insulation layer 168therebetween, has been described by way of example, the presentdisclosure may also be applied to a self-capacitance-type touch sensorCs. Each of a plurality of self-capacitance-type touch electrodes has anelectrically independent self-capacitance, and thus is used as aself-capacity-type touch sensor that senses variation in capacitance bya user touch. That is, the routing lines 156 connected to theself-capacitance-type touch electrodes are connected not only to thetouch pad 170 through the pad contact hole 174 but also to the auxiliaryconductive layer 172 through the auxiliary contact hole 176. Thereby,even if a disconnection fault of the routing line 156 occurs at theboundary of the organic encapsulation layer 144, the routing line 156 isconnected to the touch pad 170 via the auxiliary conductive layer 172,which results in increased yield.

As is apparent from the above description, a display device according tothe present disclosure includes an auxiliary conductive layer, which isconnected to a touch pad and is also connected to a routing line underan encapsulation unit. Thereby, according to the present disclosure,even if short-circuit occurs in the routing line, the routing line andthe touch pad may be electrically connected to each other via theauxiliary conductive layer. In addition, a conventional organiclight-emitting diode display device includes a touchscreen attachedthereto using an adhesive, whereas an organic light-emitting diodedisplay device of the present disclosure includes touch electrodesdisposed on the encapsulation unit, which may make a separate attachmentprocess be unnecessary, resulting in a simplified manufacturing processand reduced costs.

Although the embodiments of the present disclosure have been describedabove in detail with reference to the accompanying drawings, it will beapparent to those skilled in the art that the present disclosuredescribed above is not limited to the embodiments described above, andvarious substitutions, modifications, and alterations may be devisedwithin the spirit and scope of the present disclosure.

The various embodiments described above can be combined to providefurther embodiments. These and other changes can be made to theembodiments in light of the above-detailed description. In general, inthe following claims, the terms used should not be construed to limitthe claims to the specific embodiments disclosed in the specificationand the claims, but should be construed to include all possibleembodiments along with the full scope of equivalents to which suchclaims are entitled. Accordingly, the claims are not limited by thedisclosure.

What is claimed is:
 1. A display device, comprising: a transistor on asubstrate, the transistor including a semiconductor, a gate electrodeoverlapping the semiconductor with a gate insulation layer therebetween,a source electrode, and a drain electrode; a protective layer on thetransistor; a light-emitting element disposed on a substrate; anencapsulation unit disposed on the light-emitting element; a touchsensor disposed on the encapsulation unit; a touch pad electricallyconnected to the touch sensor; a routing line disposed between the touchpad and the touch sensor, the routing line electrically coupling thetouch pad to the touch sensor; and an auxiliary conductive layerelectrically connected to the routing line through an auxiliary contacthole penetrating through at least one of the encapsulation unit, theauxiliary conductive layer being disposed between the substrate and theencapsulation unit.
 2. The display device according to claim 1, whereinthe routing line is disposed on the encapsulation unit.
 3. The displaydevice according to claim 1, wherein the protective layer and theencapsulation unit are disposed to cover the auxiliary conductive layer,and wherein the routing line is connected to the auxiliary conductivelayer through an auxiliary contact hole, which auxiliary contact holepenetrates through the protective layer and the encapsulation unit. 4.The display device according to claim 1, further comprising a touchbuffer layer disposed between the touch sensor and the encapsulationunit, wherein the auxiliary conductive layer is electrically connectedto the routing line through an auxiliary contact hole, and the auxiliarycontact hole penetrates through the touch buffer layer, theencapsulation unit and the protective layer, wherein the auxiliaryconductive layer is electrically connected to the touch pad through apad contact hole, and the pad contact hole penetrates through theprotective layer and the touch buffer layer.
 5. The display deviceaccording to claim 1, further comprising: a touch buffer layer disposedbetween the touch sensor and the encapsulation unit; and a touchinsulating layer on the touch buffer layer, wherein the auxiliaryconductive layer is electrically connected to the routing line throughan auxiliary contact hole, and the auxiliary contact hole penetratesthrough the touch buffer layer, the encapsulation unit and theprotective layer, wherein the auxiliary conductive layer is electricallyconnected to the touch pad through a pad contact hole, and the padcontact hole penetrates through the protective layer and the touchbuffer layer.
 6. The display device according to claim 1, wherein theauxiliary conductive layer is formed using a same material on a samelayer as at least one of the gate electrode, the source electrode, orthe drain electrode.
 7. The display device according to claim 3, whereinthe encapsulation unit comprises a plurality of inorganic encapsulationlayers and at least one organic encapsulation layer disposed between theinorganic encapsulation layers, and wherein the auxiliary contact holepenetrates through the inorganic encapsulation layers and the organicencapsulation layer of the encapsulation unit, and the protective layer.8. The display device according to claim 3, wherein the encapsulationunit comprises a plurality of inorganic encapsulation layers and atleast one organic encapsulation layer disposed between the inorganicencapsulation layers, and wherein the auxiliary contact hole penetratesthrough the inorganic encapsulation layers of the encapsulation unit,and the protective layer.
 9. The display device according to claim 8,wherein an uppermost inorganic encapsulation layer of the plurality ofinorganic encapsulation layers is disposed to cover a side surface ofthe organic encapsulation layer that is exposed through the auxiliarycontact hole.
 10. The display device according to claim 1, furthercomprising a color filter disposed between the encapsulation unit andthe touch sensor.
 11. The display device according to claim 1, whereinthe touch sensor comprises a touch sensing line and a touch driving linedisposed to intersect each other above the encapsulation unit, whereinthe touch driving line comprises: first touch electrodes arranged on theencapsulation unit in a first direction; and a first bridge configuredto interconnect the first touch electrodes, and wherein the touchsensing line comprises: second touch electrodes arranged in a seconddirection intersecting the first direction; and a second bridgeconfigured to interconnect the second touch electrodes.
 12. The displaydevice according to claim 2, wherein the routing line is disposed tocover a side surface of one of the encapsulation unit.
 13. The displaydevice according to claim 1, wherein the auxiliary conductive layer isformed using a same material as at least one of an anode electrode and acathode electrode of the light-emitting element, and is disposed on aprotective layer, which is disposed to cover a thin-film transistor.